U.S. patent application number 12/256150 was filed with the patent office on 2009-05-07 for double block and bleed plug.
This patent application is currently assigned to TDW Delaware, Inc.. Invention is credited to Richard L. Goswick, Gregory L. Puckett, Kenneth L. Yeazel.
Application Number | 20090114302 12/256150 |
Document ID | / |
Family ID | 42119591 |
Filed Date | 2009-05-07 |
United States Patent
Application |
20090114302 |
Kind Code |
A1 |
Yeazel; Kenneth L. ; et
al. |
May 7, 2009 |
Double Block and Bleed Plug
Abstract
A pipe plug includes two or more pivotally connected plugging
heads that work in combination to double block and bleed a pipe. At
least one of the plugging heads has an expandable sealing element
that is in communication with an inflation source. The sealing
element may be an inflatable sealing element or a compression
packer sealing element. A passageway-sections of which may pass
through the pivotal connection and into the plugging head-carries
the inflation medium from the source to the sealing element. A
bleed port passageway is also provided that passes through the
plugging head. The leading plugging head may include a cleaning
element for sweeping away debris ahead of the plug. The plugging
heads may also include a skid plate that slideably engages the
interior surface of the pipe to properly orient the plugging heads
within the pipe.
Inventors: |
Yeazel; Kenneth L.; (Tulsa,
OK) ; Puckett; Gregory L.; (Broken Arrow, OK)
; Goswick; Richard L.; (Tulsa, OK) |
Correspondence
Address: |
GABLE & GOTWALS
100 WEST FIFTH STREET, 10TH FLOOR
TULSA
OK
74103
US
|
Assignee: |
TDW Delaware, Inc.
|
Family ID: |
42119591 |
Appl. No.: |
12/256150 |
Filed: |
October 22, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11936182 |
Nov 7, 2007 |
|
|
|
12256150 |
|
|
|
|
Current U.S.
Class: |
138/90 ; 137/312;
138/89; 138/91; 138/92; 138/93; 138/94; 138/95 |
Current CPC
Class: |
Y10T 137/5762 20150401;
F16L 55/124 20130101; F16L 55/1283 20130101; F16L 55/134 20130101;
F16L 55/132 20130101 |
Class at
Publication: |
138/90 ; 138/93;
138/94; 137/312; 138/91; 138/89; 138/92; 138/95 |
International
Class: |
F16L 55/124 20060101
F16L055/124; F16L 55/132 20060101 F16L055/132; F16K 24/02 20060101
F16K024/02 |
Claims
1. A pipe plug for temporarily plugging a pipe, said pipe plug
comprising: a carrier; and a plurality of plugging heads having a
pivotal connection one to the other, at least one plugging head in
said plurality of plugging heads having an expandable sealing
element; and a fluid circuit in communication with said expandable
sealing element; a fluid provided by said fluid circuit causing
said expandable sealing element to move between a retracted
position and an expanded position.
2. A pipe plug according to claim 1 further comprising said
expandable sealing element being selected from the group consisting
of an inflatable sealing element and a compression packer sealing
element.
3. A pipe plug according to claim 1 further comprising said fluid
circuit having a first passageway and a second passageway, said
first passageway capable of carrying said fluid to a portion of
said at least one plugging head, an open end of said second
passageway being in communication with an interior space of the
pipe when the pipe plug is in a sealing position.
4. A pipe plug according to claim 3 further comprising at least one
of said first and second passageways passing through at least one
of the pivotal connections.
5. A pipe plug according to claim 4 further comprising at least one
said pivotal connection having an annular groove, said annular
groove being in communication with at least one of said first and
second passageways.
6. A pipe plug according to claim 3 further comprising a portion of
at least one of said first and second passageways being a
tubing.
7. A pipe plug according to claim 3 further comprising a piston
plate in communication with said first passageway and said
expandable sealing element, said piston plate being moveable
between a first position and a second position, said expandable
sealing element being located between said piston plate and a
nosepiece of said at least one plugging head.
8. A pipe plug according to claim 7 further comprising said
expandable sealing element including at least one anti-extrusion
spring.
9. A pipe plug according to claim 7 further comprising an
anti-rotation pin located on said at least one plugging head.
10. A pipe plug according to claim 1 further comprising a second
plugging head in said plurality of plugging heads having a cleaning
element.
11. A pipe plug according to claim 10 further comprising said
cleaning element including a wire brush.
12. A pipe plug according to claim 1 further comprising a skid
plate, said skid plate oriented to facilitate placement of said
plurality of plugging heads within a pipe.
13. A pipe plug according to claim 1 further comprising a pivot
arm, said pivot arm being located on a leading plugging head of
said plurality of plugging heads.
14. A pipe plug for temporarily plugging a pipe, said pipe plug
comprising: a carrier; a first plugging head, said first plugging
head having a first expandable sealing element and a first pivotal
connection to said carrier; a second plugging head, said second
plugging head having a second expandable sealing element and a
second pivotal connection to said first plugging head; and an
inflation system in communication with said first and second
expandable sealing elements.
15. A pipe plug according to claim 14 further comprising said
inflation system having a first and second passageway, said first
and second passageways each capable of carrying an inflation medium
to one of said first and second expandable sealing elements
respectively.
16. A pipe plug according to claim 15 further comprising a piston
plate in communication with said first passageway and said
expandable sealing element, said piston plate being moveable
between a first position and a second position, said expandable
sealing element being located between said piston plate and a
nosepiece of said at least one plugging head.
17. A pipe plug according to claim 16 further comprising said
expandable sealing element including at least one anti-extrusion
spring.
18. A pipe plug according to claim 15 further comprising a third
passageway, an open end of said third passageway being located
downstream of said first plugging head and in communication with an
interior portion of a pipe.
19. A pipe plug according to claim 15 further comprising said first
and second passageways passing through a portion of said first and
second pivotal connections respectively.
20. A pipe plug according to claim 14 further comprising a third
plugging head having a cleaning element and a third pivotal
connection to said second plugging head.
21. A pipe plug according to claim 20 further comprising said
cleaning element being a wire brush.
22. A pipe plug according to claim 20 further comprising said third
plugging head having a skid plate, a guide wheel, and a pivot
arm.
23. A pipe plug according to claim 14 further comprising said first
plugging head and second plugging head each having a skid plate and
a guide wheel, each said skid plate and said guide wheel oriented
to facilitate placement of said first and second plugging heads
respectively within a pipe.
24. A pipe plug according to claim 23 further comprising said
second plugging head having a pivot arm.
25. A method of double-blocking a pipe, the method comprising the
steps of: lowering a first plugging head and a second plugging head
through a lateral pipe access connection, the heads being pivotally
connected relative to one another; rotating the first plugging head
and the second plugging head so that each enters a pipe connected
to the lateral pipe access connection and travels in a direction of
product flow through the pipe; positioning the first plugging head
and the second plugging head into a final sealing position within
the pipe; and expanding a sealing element on at least one of the
first and second plugging heads.
26. A method of double-blocking a pipe according to claim 25
wherein at least one said step of rotating and positioning is by at
least one skid plate that slideably engages an interior portion of
at least one of the lateral pipe access connection and the
pipe.
27. A method according to claim 25 further comprising the step of
venting an interior space of the pipe through a bleed port, a
portion of the bleed port being integral to at least one of the
plugging heads.
28. A method according to claim 25 further comprising the step of
deflating the sealing element through a bleed valve.
Description
REFERENCE TO PENDING APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 11/936,182, filed on Nov. 7, 2007, and claims
priority to that U.S. application.
FIELD OF THE INVENTION
[0002] This invention relates generally to pipe plugs, particularly
plugs for use in pipelines that carry high or low pressure fluids,
high or low temperature fluids, steam, dangerous fluids, and
environmentally hazardous fluids.
BACKGROUND OF THE INVENTION
[0003] "Double block and bleed" is a well-known term of art that
refers to setting two seals in a pipe and opening a bleed port
between the seals to ensure that the first seal is holding. Any
leakage past the first seal is contained by the second seal and
forced to exit through the bleed port. This arrangement ensures
that the pipe is completely sealed, making it safe to work on
downstream of the two seals.
[0004] Achieving double-block and bleed, however, currently
requires the use of a single, metal-to-metal plugging seal or the
use of two independent pluggers and fittings. Both approaches are
expensive; use relatively large, heavy components; and require a
lot of equipment to properly install. Additionally, the
metal-to-metal plugging seal approach does not allow for bypassing
pipeline product through a fitting. If a bypass is required, a
second fitting must be installed upstream of the plugging seal.
Therefore, a need exists for a double block and bleed plug that is
less expensive, smaller and lighter weight, and easier to install
than the current approaches. None of the prior art alone or in
combination meets this need or renders the present invention
obvious.
[0005] For additional information relating to pipe pluggers,
reference may be had to the following previously issued United
States patents.
TABLE-US-00001 Patent Number Inventor Title 386,446 Bailey
Apparatus For Detecting Leaks In Soil and Other Pipes 411,978
Chisholm Pipe Stopper 1,181,984 Arni Test Plug 1,221,733 Henderson
Test Plug 2,279,257 Svirsky Expansible Closure Means For Conduits
2,812,778 Ver Nooy Pipe Line Plugger 2,886,068 Ver Nooy Pipe Line
Plugger 2,906,295 Ver Nooy Pipe Line Plugger 3,154,106 Ver Nooy
Pipeline Plugger 3,442,294 Bischoff et al. Closure Means For Use
During Pressure Testing Of Pipes or The Like 3,665,966 Ver Nooy
Pipe Plugger 3,774,646 Smith Line Stopping Assembly Using An
Inflatable Element 3,774,647 Saha et al. Line Stopping Assembly
Using An Inflatable Element 3,902,528 Tartabini et al. Pneumatic
Plug For Hydraulic Conduits 4,040,450 Boundy Pipe Sealing Apparatus
4,064,912 Petrone Gas Main Stopper 4,202,377 Harrison Pipe Cleaning
and Plugging Apparatus 4,505,295 Quin et al. Apparatus For
Inserting A Shut-Off Device Laterally Into A Pipe 4,682,631 Wilger
et al. Sealing Apparatus For A Valve Body Opening 5,029,614 Lara et
al. Tandem Seal System For Testing Pipelines 5,082,026 Smith
Pipeline Plugger 5,297,581 Godfrey Pipeline Plugger 5,844,127
Berube et al. Apparatus For Isolating or Testing A Pipe Segment
6,062,262 Tash Water Drain Pipe Test Plug Device 6,289,935 Tash
Drainpipe Test Plug Device 6,601,437 Gotowik Apparatus For Testing
or Isolating A Segment Of Pipe 6,659,133 Russell Insertable Line
Stopper Plug For Pipelines 7,240,697 Beebe et al. Apparatus and
Method For Isolating and Testing A Segment Of Pipelines 7,270,139
Calkins et al. Cam-Assisted, Wedge Actuated, Metal-to-Metal Seal,
Block and Bleed Plugging Tool 7,281,543 Calkins et al. Apparatus,
Systems and Methods for Plugging a High Temperature Pipe
2007/0018452 Lee Pipe Interruption Fitting 2008/0017390 Bowie
Isolation Tool EP 0488966 A1 Ravetti Stopper Device For Gas Tubes
WO2007/117154 Aleksandersen Smartplug with Wheel Centralizer et
al.
BRIEF SUMMARY OF THE INVENTION
[0006] The pipe plug according to this invention comprises one
plugging head with a sealing element pivotally connected by a yoke
to a carrier, and a second plugging head with a sealing element
pivotally connected by a yoke to the first plugging head. When
lowered through a lateral pipe access connection and placed in a
final sealing position within a pipe, the first sealing element
prevents flow of product in the pipe and the second sealing element
captures any leakage past the first sealing element and forces that
leakage out through a fitting. The fitting may be connected to a
sleeve welded around the pipe and located downstream of the pipe
access connection. The sleeve is required only if the stabilization
pad forces on the pipe are excessive.
[0007] To help position each sealing element within the pipe, the
pipe plug includes a set of wheels connected to each plugging head.
Each wheel in the set of wheels impinges a portion of the pipe at
some point during positioning of the pipe plug within the pipe,
thereby causing the sealing elements to rotate into their final
sealing position within the pipe. A stabilization pad, connected to
a nose of each plugging head, prevents deformation of the sealing
elements.
[0008] A spring-loaded pivot arm, pivot pin, and pivot wheel
connected to the second plugging head allow the yoke that connects
the two plugging heads to rotate freely into its proper position
within a pipe. The pivot arm also has an outward-facing raised
taper projection located behind the pivot wheel that helps prevent
the pivot wheel from becoming entrapped in a pipe access connection
when installing the pipe plug into the pipe or removing the pipe
plug from the pipe. A guide wheel connected to the first plugging
head helps prevent the first plugging head and the yoke connected
to the carrier from becoming entrapped during the installation or
removal process.
[0009] The pivotal arrangement of the plugging heads may be
expanded to include a third plugging head. The third, or lead head,
includes the pivot arm. All three plugging heads may include
sealing elements. Alternatively, only the first and second plugging
heads may have sealing elements with the third plugging head having
a cleaning element such as a wire brush. The wire brush serves to
sweep away debris ahead of the pipe plug.
[0010] The guide wheel connected to the first plugging head may be
replaced by a skid plate that slideably engages the access
connection and helps prevent the first plugging head and the yoke
connected to the carrier from becoming entrapped during the
installation or removal process. Similarly, the guide wheel on the
second plugging head may be replaced by a skid plate that helps
prevent entrapment and also slideably engages a portion of the pipe
at some point during positioning of the pipe plug. Skid plates may
also be used in place of guide wheels when three plugging heads are
used.
[0011] The sealing elements used may be an expandable sealing
element such as an inflatable sealing element or a compression
packer sealing element. An inflation system supplies an inflation
medium that travels along a passageway and inflates the expandable
sealing element. A portion of the passageway is external to the
plugging head and may be a tubing. Another portion of the
passageway may be internal to the pipe plug, passing through parts
of the carrier, yoke, and yoke pin (in the case of the first
sealing element) and into the plugging head. The yoke pin may
include an annular groove that provides continuity for the
passageway as it exits the carrier and enters the yoke. A similar
passageway may also be provided to inflate a second or third
expandable sealing element. A third passageway--which may also pass
through the carrier, yoke, and yoke pin--provides a bleed port for
any leakage past the first inflatable sealing element.
[0012] A better understanding of the invention will be obtained
from the following detailed description of the preferred
embodiments taken in conjunction with the drawings and the attached
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Preferred embodiments of the invention will now be described
in further detail. Other features, aspects, and advantages of the
present invention will become better understood with regard to the
following detailed description, appended claims, and accompanying
drawings (which are not to scale) where:
[0014] FIG. 1 is an isometric view of the pipe plug.
[0015] FIG. 2 is a reverse isometric view of the pipe plug.
[0016] FIG. 3 is an isometric view of the pipe plug in its final
sealing position within a pipe having a bleed port.
[0017] FIG. 4 is a view of the pipe plug in its final sealing
position within a pipe.
[0018] FIG. 5 is a view of the pipe plug as it is being lowered
through a pipe access connection.
[0019] FIG. 6 is a view of the pipe plug as it begins its
transition into the pipe.
[0020] FIG. 7 is a view of the pipe plug as it travels along the
pipe.
[0021] FIG. 8 is a view of the pipe plug as its plugging heads and
their sealing elements begin to rotate into a final sealing
position within the pipe.
[0022] FIG. 9 is a view of the pipe plug with an additional
plugging head and in its final sealing position within the pipe. A
skid plate on each head helps prevent the yoke and head from
becoming entrapped in the access connection to the pipe during
installation and removal.
[0023] FIG. 10 is a view of the pipe plug with an additional head
that includes wire brushes to sweep debris ahead of the plug.
[0024] FIG. 11 is a view of the pipe plug having two plugging heads
with inflatable sealing elements. A bundle of steel tubes forms
part of two passageways that each supply a source of inflation to
one of the sealing elements. A third passageway provides a bleed
port.
[0025] FIG. 12 is a view taken along section line 12-12 of FIG. 11.
Bulkhead fittings connect the supply line portions of the
passageways with the steel tube portion of the passageways located
within the housing.
[0026] FIGS. 13A and 13B are plumbing schematics for the pipe plug
when equipped with inflatable sealing elements. The passageways
pass through various portions of the pipe plug in order to supply
an inflation medium to the inflatable sealing elements and provide
a bleed port.
[0027] FIG. 14 is a view of a pipe plug having two plugging heads
with compression packer sealing elements. A bundle of steel tubes
forms part of two passageways that each supply hydraulic fluid used
to actuate the sealing elements. A third passageway provides a
bleed port.
[0028] FIG. 15 is a view of the pipe plug as it would appear in a
ready-to-seal position within a pipe (not shown). Each packer
sealing element resides between a moveable piston plate and a fixed
nose. The piston plate and nose protect the sealing elements during
installation and removal.
[0029] FIG. 16 is a plumbing schematic for the pipe plug when
equipped with packer sealing elements. Two independent passageways
each provide hydraulic fluid to one of the two plugging heads. Each
passageway provides means of hydraulically pressurizing a
cylindrical cavity in communication the movable piston plate.
[0030] FIG. 17 is a cross-sectional view of the trailing plugging
head with the packer seal in a retracted position. The packer seal
has two anti-extrusion springs. The movable piston plate has a
cylindrical protrusion that enables the piston plate to act in a
manner similar to a hydraulic cylinder rod.
[0031] FIG. 18 is a cross-sectional view of the trailing plugging
head with the packer seal in an expanded position.
[0032] FIG. 19 is a partial cross-sectional view of the trailing
plugging head. The plugging head is held in its correct orientation
by an anti-rotation pin that threads into the nosepiece, piston
plate and yoke.
[0033] FIG. 20 is a partial-cross sectional view of the leading
plugging head.
[0034] FIG. 21 is an isometric view of the pipe plug illustrating
an alternate porting arrangement that does not include drilling the
yoke pin to act as a conduit as previously shown in FIG. 13A.
Instead, the yoke arm includes fittings that are in communication
with the inflation passageways and bleed passageway.
[0035] FIG. 22 is a reverse isometric view the pipe plug
illustrating the alternate porting arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] It is to be understood that the invention that is now to be
described is not limited in its application to the details of the
construction and arrangement of the parts illustrated in the
accompanying drawings. The invention is capable of other
embodiments and of being practiced or carried out in a variety of
ways. The phraseology and terminology employed herein are for
purposes of description and not limitation.
[0037] Elements shown by the drawings are identified by the
following numbers:
TABLE-US-00002 10 Pipe Plug 12 Carrier 13 Plug 14 Yoke 15 End Plate
16 Yoke Pin 17 Annular Groove 18 Yoke Mount 19 O-Ring 20 Plugging
Head 21 Plugging Head 22 Sealing Element 23 Sealing Element 24
Mounting Plate 25 Inlet 26 Nosepiece 28 Nose 30 Stabilization Pad
32 Wheel 34 Wheel 36 Guide Wheel 37 Skid Plate 38 Yoke 39 End Plate
40 Yoke Pin 41 Annular Groove 43 O-Ring 45 End Plate 50 Packer Seal
51 Piston Plate 52 Angled Surface 53 Angled Surface 54 Cylindrical
Protrusion 55 O-Ring 56 O-Ring 57 O-Ring 58 O-Ring 59 Plug 60
Plugging Head 62 Sealing Element 63 Sealing Element 64 Mounting
Plate 65 Inlet 66 Nosepiece 68 Nose 70 Stabilization Pad 72 Pivot
Arm 73 Projection 74 Pivot Arm Wheel 76 Pivot Arm Pin 78 Spring 80
Pivot Arm Stop 82 Wheel 84 Wheel 86 Wheel 87 Skid Plate 90 Sleeve
92 Fitting 94 Port 102 Cleaning Element 104 Brush 108 External Port
Fitting 110 Inflation System/ Fluid Circuit 112 Inflation Source
113 Inflation Source 114 Tube Bundle 115 Valve 116 Valve 117 Valve
118 Valve 119 Valve 120 Inflation Passageway 122 Fitting 124 Elbow
126 Fitting 128 Lateral Run 130 Longitudinal Run 141 Annular Groove
143 O-Ring 160 Inflation Passageway 162 Fitting 164 Elbow 166
Fitting 168 Lateral Run 170 Lateral Run 180 Tee 181 Tee 190 Bleed
Port Passageway 192 Fitting 194 Elbow 196 Fitting 198 Open End 200
Cylindrical Cavity 205 Bleed Fitting 210 Threaded Shaft 220
Cylindrical Protrusion 225 Anti-Rotation Pin 230 Piston Plate 232
Threaded Shaft 234 Cylindrical Projection 235 Cylindrical Cavity
240 Packer Seal 242 Angled Surface 243 Angled Surface 244
Anti-Extrusion Spring 245 Anti-Extrusion Spring 246 Anti-Extrusion
Spring 247 Anti-Extrusion Spring 250 Yoke Arm 255 Yoke Arm
[0038] Referring to the drawings and first to FIGS. 1 and 2, the
pipe plug 10 comprises a plugging head 20 and a plugging head 60
that are pivotally connected to each other by a yoke 38 that
rotates about a yoke pin 40. Plugging head 20, in turn, is
pivotally connected to carrier 12 by yoke 14. Yoke 14 rotates about
a yoke pin 16 contained within a yoke mount 18 connected to carrier
12. Carrier 12 is well-known in the art and is of the type of
control bar head typically used to vertically lower, rotate, and
position a plugging head within a pipe P for the purpose of
temporarily blocking the pipe P. Similarly, plugging head 20 and
plugging head 60 also are well-known in the art and are of the type
typically used to temporarily block a pipe P.
[0039] Plugging head 20 includes a sealing element 22, a nosepiece
26 and a nose 28. A stabilization pad 30 mounts to nose 28 at a
location substantially parallel to and offset from yoke pin 16.
Stabilization pad 30 helps prevent deformation of sealing element
22 by countering the rotational moment generated by seal force
about yoke pin 16. Nose 28 also includes a guide wheel 36 that
helps prevent yoke 14 and plugging head 20 from becoming entrapped
in the access connection to pipe P during their installation into
and removal from the pipe P.
[0040] Plugging head 60 includes a sealing element 62, a nosepiece
66 and a nose 68. To ensure that yoke 38 rotates freely into its
proper position within the pipe P, a pivot arm 72 is rotationally
affixed to nose 68. The pivot arm 72 includes a pivot wheel 74,
pivot arm pin 76, and spring 78. The spring 78, along with two
pivot arm stops 80 mounted to nose 68, allows the pivot arm 72 to
rotate outward and hold its position. Outward-facing projections 73
on the pivot arm 72 and located substantially right behind pivot
arm wheel 74 help prevent the pivot arm wheel 74 from becoming
entrapped in the access connection to pipe during installation of
the second plugging head 60. A stabilization pad 70 mounts to nose
68 at a location substantially opposite that of pivot arm 72.
Stabilization pad 70 helps prevent deformation of sealing element
62 by countering the rotational moment generated by seal force
about yoke pin 40.
[0041] Referring now to FIGS. 3 and 4, pipe plug 10 travels
downwardly through an access connection--typically comprised of a
housing H, sandwich valve V, and fitting F--until yoke mount 18
comes to rest on a bottom portion of the pipe P, with plugging head
20 and plugging head 60 substantially aligned with each other and
sealing elements 22 and 62 in their final sealing position. When
sealing element 22 is in its final sealing position, its outer
surface of sealing element is engaged with the inner wall of pipe P
and wheels 32A, 32B, and 34, as well as guide wheel 36, do not
impinge on any portion of the pipe P. In this position, sealing
element 22 prevents flow of product in the pipe P. When sealing
element 62 is in its final sealing position, its outer surface is
engaged with the inner wall of pipe P and wheels 82, 84, and 86 do
not impinge on any portion of the pipe P. Pivot arm 72 and pivot
arm wheel 74 are held in an outward-facing position against the
pipe P by spring 78.
[0042] Sealing element 62 captures any leakage past sealing element
22 and forces that leakage out through a fitting 92. Fitting 92 may
be connected to a sleeve 90 welded around the pipe and located
downstream of the pipe P access connection. Fitting 92 is of the
type well-known in the art to provide a bleed port.
[0043] As illustrated by FIGS. 5 and 6, pipe plug 10 travels
downwardly through housing H, sandwich valve V, and fitting F,
until pivot arm wheel 74 impinges on a bottom portion of pipe P,
causing yoke 38 to begin rotation about yoke pin 40. As pipe plug
10 is further lowered into the fitting, yoke 38 continues to rotate
about yoke pin 40 until wheel 82 impinges a bottom portion of pipe
P. As illustrated by FIG. 7, the rotation of yoke 38 continues
until wheel 84 and then wheel 86 impinge on a bottom portion of the
pipe. As wheel 86 impinges on a bottom portion of the pipe P,
plugging head 20 begins its entry into pipe P. As illustrated by
FIGS. 7 and 8, at some point in this process of rotating plugging
head 60, pivot arm wheel 74 impinges on a top portion of pipe P and
causes pivot arm 72 to rotate out of the way.
[0044] Referring once again to FIG. 8, as plugging head 60 becomes
substantially in alignment with the inside diameter of pipe P, pipe
plug 10 continues its downward travel and plugging head 20 begins
its transition into position within pipe P as wheels 32A and 32B
impinge on a bottom portion of pipe P, causing yoke 14 to rotate
about yoke pin 16. As yoke 14 continues to rotate, plugging head 20
becomes more substantially in alignment with the inside diameter of
pipe P. Wheel 34 then impinges on a bottom portion of pipe P,
causing yoke 14 to continue its rotation until sealing element 22
rotates into a final sealing position. When yoke mount 18 comes to
rest on a bottom portion of pipe P, sealing elements 22 and 62 are
in their final sealing positions (see FIGS. 3 and 4) and pipe plug
10 is stable and capable of resisting pipeline pressure loads.
[0045] FIGS. 9 and 10 illustrate other preferred embodiments of
pipe plug 10. An additional plugging head 21 may be pivotally
connected to first plugging head 20 with second plugging head 60
being pivotally connected to the additional plugging head 21.
Second plugging head 60 may include a sealing element 62 or a
cleaning element 102. Cleaning element 102 is preferably a wire
brush-type element 104 for moving or brushing away dirt and debris
ahead of pipe plug pig 10. In using sealing element 62, any leakage
past plugging head 20 or 21 is forced out through a port 94 and
fitting 92. If using cleaning element 102, any leakage past
plugging head 20 is forced out through port 94 and fitting 92.
[0046] A skid plate 37 may replace guide wheel 36 on plugging heads
20 and 21. Skid plate 37 is mounted opposite wheel 34 on the
angular surface of nose 28. The skid plate 37 may be constructed of
suitable materials ranging from thermoplastic to brass. As pipe
plug 10 is lowered into the access connection to pipe P, skid plate
37 comes into contact with and slideably engages the interior
surfaces of the access connection, thereby preventing yoke 14 and
plugging head 20 and 21 from becoming entrapped.
[0047] Similarly, a skid plate 87 may replace wheel 86 on plugging
head 60. Skid plate 87 is mounted on an angular surface of nose 68
and opposite pivot arm 72. The skid plate 87 may be constructed of
suitable materials ranging from thermoplastic to brass. As pipe
plug 10 starts its entry into pipe P, skid plate 87 comes into
contact with and slideably engages a bottom portion of pipe P. As
skid plate 87 impinges on the bottom portion of the pipe P,
plugging head 21, and then plugging head 20, begins its entry into
pipe P. At some point in this process of rotating plugging head 60,
pivot arm wheel 74 impinges on a top portion of pipe P and causes
pivot arm 72 to rotate out of the way. The plugging heads 20, 21,
and 60 then become oriented into their final sealing positions in a
manner similar to that previously described.
[0048] Referring now to FIGS. 11 to 13B, pipe plug 10 may include
inflatable sealing elements 23 and 63 on plugging heads 20 and 60,
respectively. Alternatively, an arrangement similar to that shown
in FIGS. 9 and 10 may be employed, with one or more heads 20, 21,
and 60 having inflatable sealing elements. Sealing elements 23 and
63 are in communication with an inflation system 110. Inflation
system 110 preferably includes one or more liquid or gas medium
inflation sources 112 and 113. Inflation sources 112 and 113 may be
a compressor, a compressed gas tank or a pump. Two passageways 120
and 160 connect the inflation sources 112 and 113 respectively to
the sealing elements 23 and 63, and a third passageway 190 provides
a bleed port. Valves 115 and 117 provide a means of isolating and
controlling the inflation pressure provided by inflation sources
112 and 113, respectively. Valve 116 provides a means of
controlling any leakage out of the bleed port.
[0049] As described below, each passageway 120, 160, and 190
includes various fittings and connectors, with some portions of the
passageways 120, 160, and 190 passing through elements of pipe plug
10. For ease of description and reference, various sections of each
passageway 120, 160, and 190 have been given letter designations.
For example, 120A refers to an external supply line of passageway
120.
[0050] After pipe plug 10 has been properly oriented within pipe P,
inflatable sealing elements 23 and 63 are inflated, either in
concert or in series, so that they come into contact with and
sealably engage an interior surface of pipe P. Inflation sources
112 and 113 provide an inflation medium, preferably air, an inert
gas, or a liquid to sealing elements 23 and 63 by way of
passageways 120 and 160. Passageway 190 provides a bleed port.
Depending on the pipeline product, the bleed port may vent to a
reservoir (not shown) or to ambient.
[0051] Considering inflation passageway 120 first, a supply line
section 120A runs from inflation source 112 through valve 115 and
tee 181 to bulkhead fitting 122 located on an external surface of
housing H. Tee 181 is in communication with a bleed valve 119 and a
vent. Fitting 122 is in communication with an elbow connector 124
that connects to the upper end of tubular section 120B. Tubular
section 120B is preferably a steel tube in the shape of a
compression spring. The lower end of tubular section 120B connects
to a fitting 126 on carrier 12. Internal to carrier 12 is
passageway section 120C. Passageway section 120C is constructed so
that it aligns with one of the annular grooves 17 in yoke pin 16.
O-rings 19, which are located on either side of the annular groove
17, provide sealing engagement and help to maintain the integrity
of passageway 120 as it enters yoke pin 16.
[0052] Within yoke pin 16 is passageway section 120D. Because of
the physical arrangement of carrier 12, yoke 14, and plugging head
20, passageway section 120D makes two angular jogs as it passes
through yoke pin 16. Each angular jog is preferably a right angle
jog. Fabricating one of the angular jogs in yoke pin 16 requires
drilling into an end of yoke pin 16 and creating a longitudinal run
128. A plug 13 seals the exposed open end of the longitudinal run
128 and maintains the integrity of passageway 120 as it passes
through yoke pin 16. A longitudinal run 130, which intersects
lateral run 128, is in alignment with a second annular groove 17.
Passageway section 120D exits yoke pin 16 and enters yoke 14 as
passageway 120E.
[0053] An end plate 15 helps to secure yoke pin 16 into its proper
position and ensure that the annular grooves 17 are in proper
alignment with passageway sections 120C, 120D, and 120E. Passageway
section 120E passes through a portion of yoke 14 and into plugging
head 20, where passageway section 120E makes an angular jog and
engages an inlet 25 of sealing element 23. Because of the above
described arrangement and continuity of passageway 120, an
inflation medium may pass from inflation source 112 to sealing
element 23, thereby inflating sealing element 23. Prior to removing
pipe plug 10 from the pipe, sealing element 23 may be deflated by
opening bleed valve 119, which is connected to tee 181 on
passageway section 120A.
[0054] Inflation passageway 160 may be constructed in a manner
similar to inflation passageway 120. In a preferred embodiment, a
supply line section 160A runs from inflation source 113 through
valve 117 and tee 180 to bullhead fitting 162, which is in
communication with an elbow connector 164. Tee 180 is in
communication with a bleed valve 118 and a vent. Elbow connector
164 connects to the upper end of tubular section 160B. Tubular
section 160B is preferably a steel tube in the shape of a
compression spring and formed relative to tubular section 120B.
Tubular section 160B, together with sections 120B and 190B, form a
spring-like tube bundle 114. The lower end of tubular section 160B
connects to a fitting 166 on carrier 12.
[0055] Internal to carrier 12 is passageway section 160C. Similar
to passageway section 120C, passageway section 160C is constructed
so that it aligns with one of the annular grooves 17 in yoke pin
16. O-rings 19 provide sealing engagement for the passageway 120
has it passes through annular groove 17. Within yoke pin 16 is
passageway section 160D. As was the case with passageway section
120D, passageway section 160D makes two angular jogs as it passes
through yoke pin 16. Each angular jog is preferably a right angle
jog. A plug 13 seals the exposed open end of the lateral run 168
and maintains the integrity of passageway 160 as it passes through
yoke pin 16.
[0056] As passageway section 160D exits yoke pin 16 it aligns with
a second annular groove 17. The annular groove 17 provides
continuity between passageway sections 160D and 160E. Passageway
section 160E then passes through a portion of yoke 14 and nose 28
of plugging head 20. Because of the physical relationship between
yolk 14 and nose 28, passageway section 160E makes two angular jogs
as it travels toward sealing element 63. Again, these angular jogs,
as with all the angular jogs described herein, are preferably right
angle jogs. Annular groove 141 and O-rings 143 provide continuity
of passageway section 160E between plugging head 20 and yoke 28.
The annular groove 141 is located in a cylindrical portion
connected to nose 28.
[0057] Passageway section 160E exits plugging head 20 and aligns
with an annular groove 41 in yoke pin 40. O-rings 43 provide a seal
for the annular groove 41. Passageway 160 then continues through
yoke pin 40 as passageway section 160F. Passageway section 160F is
constructed in a manner similar to passageway sections 120D and
160D. A plug 45 seals the lateral run 170. As passageway section
160F exits yoke pin 40 it aligns with a second annular grove 41 and
enters yoke 38 as passageway section 160G. An end plate 39 helps
secure and position yoke pin 40 so that the annular grooves 41 are
in their proper alignment with passageway sections 160F and 160G.
Passageway section 160G enters plugging head 60 and makes an
angular jog to engage inlet 65 of sealing element 63.
[0058] Because of the above described arrangement and continuity of
passageway 160, an inflation medium may pass from inflation source
113 to sealing element 63, thereby inflating sealing element 63.
Prior to removing pipe plug 10 from the pipe, sealing element 63
may be deflated by opening bleed valve 118, which is connected to
tee 180 on passageway section 160A.
[0059] Bleed port passageway 190 has a vent line section 190A and a
tubular section 190B. Vent line portion 190A runs from bulkhead
fitting 192 located on an external surface of housing H to bleed
valve 116. Fitting 192 is in communication with an elbow connector
194 that connects to the upper end of tubular section 190B. Tubular
section 190B is preferably a steel tube in the shape of a
compression spring. The lower end of tubular section 190B connects
to a fitting 196 on carrier 12. Internal to carrier 12 is
passageway section 190C. Passageway section 190C is constructed so
that it aligns with one of the annular grooves 17 in yoke pin
16.
[0060] Within yoke pin 16 is passageway section 190D, which makes
two angular jogs as it passes through yoke pin 16. A plug 13 seals
the exposed open end of the longitudinal run. Similar to passageway
sections 120D and 160D, passageway section 190D aligns with a
second annular groove 17 and enters yoke 14 as passageway section
190E. Passageway section 190E passes through a portion of yoke 14
and into plugging head 20 so that its open end 198 is exposed to
the interior space between plugging heads 20 and 60. Any leakage
past plugging head 20 is vented by passageway 190 through its open
end 198.
[0061] Referring now to FIGS. 14 and 15, plugging heads 20 and 60
may each include a compression packer seal design having a packer
seal 50, 240 in communication with a hydraulic fluid system 110.
Packer seals work over a wider range of pipe inner diameters than
standard sealing elements because standard sealing elements are
ground for the actual pipe inner diameter. The packer seal design
embodiment of pipe plug 10 orients itself in a sealing position
within pipe P in a substantially similar manner as the standard
seal design (FIGS. 1 to 10) and inflatable seal designs (FIGS. 11
to 13) and shares many of the components of those designs. For
example, pipe plug 10 includes a carrier 12, yokes 14 and 38, yoke
pins 16 and 40--which may have a different physical configuration
than the carrier 12, yokes 14, 38 and yoke pins 16, 40 used in the
standard and inflatable seal designs--, nose 28 and 68, skid plates
37 and 87, wheels 34, pivot arm 72, pivot arm wheel 74, pivot arm
pin 76, spring 78, passageways 120, 160 and 190, and assorted
hydraulic fittings. Each nose 28, 68 includes a stabilization pad
30, 70 to resist rotational loads and rotation about the respective
yoke pin 16, 40 as previously described. The use of a standard
control bar head to resist the pressure loads generated by the
pipeline pressure does not place the major bending loads into the
fitting F. This is accomplished by reacting bending load forces
through the foot of yoke mount 18 against the bottom of pipe P and
through carrier 12 against the access hole in pipe P.
[0062] In a preferred embodiment, plugging heads 20 and 60 are
inserted into a pipe P with the packer seals 50 and 240 in a
retracted or relaxed position. In the relaxed position, the outer
diameters of the packer seals 50, 240 are typically smaller than
the inner diameter of the pipe P. Subsequently, packer seal 50 is
compressed between two angled surfaces 52 and 53 formed by fixed
nosepiece 26 and a movable piston plate 51, respectively, on
plugging head 20. Similarly, packer seal 240 is compressed between
two angled surfaces 242 and 243 formed by fixed nosepiece 66 and a
movable piston plate 230, respectively, on plugging head 60. The
packer seal 50, 240 is compressed and forced outwardly in a radial
direction to impinge the interior wall surface of pipe P and create
a barrier.
[0063] Plugging head 20 is the primary sealing mechanism and
plugging head 60 is the secondary sealing mechanism. The position
of the two packer seals 50, 240 downstream from the access opening
to pipe P, enables the pipeline product to be routed through a port
in the side of the housing H and provides a means of bypassing
product flow around pipe plug 10 and the work that is being done to
pipe P. As in other embodiments described herein, one or more
additional plugging heads 21 may be employed in combination with
plugging heads 20 and 60 (see e.g. FIGS. 9 and 10). Alternatively,
one plugging head 20 or 60 may be employed as a single plugger but
this single plugger would not provide the double block and bleed
redundancy and safety that two or more plugging heads 20, 60
provide.
[0064] As illustrated in FIGS. 17 and 18, piston plate 51 on
plugging head 20 is designed with a cylindrical protrusion 54
having two grooves to accept O-rings 55 and 56 (or other similar
seals which are well-known in the art). The purpose of cylindrical
protrusion 54 is to enable piston plate 51 to act in a manner
similar to a hydraulic cylinder rod. The cylindrical protrusion 54,
with O-rings 55 and 56, slips inside a cylindrical cavity 200 in
the end of yoke 14 and thus completes the design of a basic,
single-acting, hydraulic cylinder. As illustrated in FIG. 16, yoke
14 has internal passageways 120, 160 and 190 to provide means of
hydraulically pressurizing cylindrical cavity 200 as well as vent
198. Passageways 120, 160 and 190 may be routed to yoke 14 in a
manner substantially similar to that as previously described. A
plug 59 seals the end of passageway section 190E.
[0065] Once the pipe plug 10 is set into its final sealing position
in pipe P, piston plate 51 is hydraulically pressurized and caused
to move against packer seal 50. Packer seal 50 is preferably an
elastomeric seal that is compliant to the wall of pipe P. Packer
seal 50 has two anti-extrusion springs 244 and 245. Hydraulic fluid
is pumped into cylindrical cavity 200 located at the end of
passageway section 120E in yoke 14 and pushes piston plate 51
against packer seal 50. The packer seal 50 is compressed against
the angled surface 52 of the nosepiece 26. As the piston plate 51
pushes against the packer seal 50, the angled surface 53 of the
piston plate 51 and angled surface 52 of nosepiece 26 distort the
packer seal 50 and cause it to distend in an outwardly radial
direction until it impinges the wall of pipe P. Anti-extrusion
springs 244 and 245 prevent the elastomer from extruding between
the pipe P and piston plate 51 and nosepiece 26. Thus packer seal
50 creates a barrier within pipe P.
[0066] Referring now to FIG. 19, plugging head 20 is held in its
correct orientation relative to yoke 14 by way of nosepiece 26 and
anti-rotation pin 225. Nosepiece 26 is threaded onto a threaded
shaft 210 which is part of yoke 14. An anti-rotation pin 225, which
is threaded and sealed into nosepiece 26, is then used to properly
orient nose 28 relative to yoke 14. The seal between anti-rotation
pin 225 and nosepiece 26 may be a pipe thread, an O-ring 57, 58
(see FIG. 17) or other seal well-known in the art. Anti-rotation
pin 225 passes through a hole in nosepiece 26, through a hole in
piston plate 51 and into a hole in yoke 14, thereby being
maintained in proper orientation to each other.
[0067] Referring now to FIG. 20, plugging head 60 is very similar
to plugging head 20 but does not have the same hydraulic porting.
Only passageway 160 travels through yoke 38 (see FIG. 16).
Passageway 160 provides means of hydraulically pressurizing a
cylindrical cavity 235 in communication with piston plate 230. A
cylindrical protrusion 234 on piston plate 230 enables piston plate
230 to act in a manner similar to a hydraulic cylinder rod. Because
of the separate porting arrangement to plugging head 60, packing
seal 240 is actuated independently of packing seal 50. This
provides a redundant system which is inherently safer than a system
which relies upon a single fluid circuit to actuate two or more
seals. The failure of one hydraulic system 120, 160, therefore,
does not cause pipe plug 10 to lose all sealing integrity within
pipe P. This redundancy is also a feature of the inflatable seal
designs (FIGS. 11 to 13) Once the pipe plug 10 is set into its
final sealing position in pipe P, piston plate 230 is hydraulically
pressurized and caused to move against packer seal 240. Similar to
packer seal 50, packer seal 240 is preferably an elastomeric seal
that is compliant to the wall of pipe P. Packer seal 240 has two
anti-extrusion springs 246 and 247 that serve a similar purpose as
springs 244 and 245 (described previously). Hydraulic fluid is
pumped into cylindrical cavity 235 located at the end of passageway
section 160G in yoke 38 and pushes piston plate 230 against packer
seal 240. The packer seal 240 is compressed against the angled
surface 242 of the nosepiece 66. Nosepiece 66 is threaded onto a
threaded shaft 232. Nose 68 is held in its correct orientation
relative to yoke 38 in a manner similar to that as described for
nose 28. As the piston plate 230 pushes against the packer seal
240, the angled surface 243 of the piston plate 240 and angled
surface 242 of nosepiece 66 distort the packer seal 240 and cause
it to distend in an outwardly radial direction until it impinges
the wall of the pipe. Thus packer seal 240 creates a barrier when
pipe plug 10 is set within the pipe.
[0068] The loads exerted by skid plates 37, 87 against the bores of
the housing H, valve V and fitting F should be reduced during
installation and retraction of the plugging heads 20, 60. The
reduced loads are due to the packer seals 50, 240 being encased
between two steel members 26, 51 and 66, 230, respectively and not
exposed to the bores as are the standard sealing elements (e.g.
sealing element 22). The standard sealing elements are deformed by
the aforementioned bores during the installation and retraction
process, thus causing reaction loads on the skid plates 37, 87.
Because the packer seals 50, 240 are protected, each may be re-used
in subsequent plugging applications.
[0069] Referring now to FIGS. 21 and 22, the fluid circuit design
for use with inflatable seals or packer seals can be done many
different ways by someone skilled in the art. For example,
hydraulic hoses (not shown) may be used instead of porting through
the yokes 14, 38. A preferred embodiment--which does not include
drilling yoke pin 16 to act as a conduit as previously shown in
FIG. 13A--includes machining yoke arm 250 to accept fittings 166
and 196. Yoke arm 255 is machined to accept fitting 126. Bleed
fittings 205 are provided to bleed air out of cylindrical cavities
200 and 235 (see also FIGS. 17 and 20).
[0070] While an improved double block and bleed plug has been
described with a certain degree of particularity, many changes may
be made in the details of construction and the arrangement of
components without departing from the spirit and scope of this
disclosure. It is understood that an improved double block and
bleed plug is not limited to the embodiments set forth herein for
purposes of exemplification, but is to be limited only by the scope
of the attached claims, including the full range of equivalency to
which each element thereof is entitled.
* * * * *